1. Field of the Invention
The present invention relates to an update system and an update method adopted to update search data that are used in a navigation apparatus or the like.
2. Description of the Related Art
There is a technology known in the related art adopted in a car navigation apparatus, whereby a map is divided into a plurality of units, map data files are created in correspondence to each of the units and the map data files are updated in units of the individual files (see, for instance, Japanese Laid Open Patent Publication No. 2001-56823). In addition, there is a technology known in the related art adopted to provide map information services through computer communication, whereby only the map data that need to be newly delivered are transmitted without transmitting any map data that are already present in the display memory at a map data display terminal (see, for instance, Japanese Laid Open Patent Publication No. H 11-295084).